Can you think of any three-dimensional shape that comprises of exactly two surfaces?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Jack was having a candle light dinner with his girlfriend. Suddenly a cold gush of wind entered through the open window and three of the ten candles were extinguished. Assuming that none of the other candles were extinguished.

How many candles are they left with in the end ?

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Can you count the number of triangles in the picture below?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?